[Hotword] Implement IsHotwordHardwareAvailable() using device types.

chrome/browser/extensions/component_loader_unittest.cc

Index: chrome/browser/extensions/component_loader_unittest.cc
diff --git a/chrome/browser/extensions/component_loader_unittest.cc b/chrome/browser/extensions/component_loader_unittest.cc
index c8625b1b78e07507d44731dc4f7c71c66b12cef0..363f7a530d334b7bb189fc0a6bbe29859ab6bfa4 100644
--- a/chrome/browser/extensions/component_loader_unittest.cc
+++ b/chrome/browser/extensions/component_loader_unittest.cc
@@ -25,6 +25,10 @@
 #include "extensions/common/manifest_handlers/background_info.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_CHROMEOS)
+#include "chromeos/audio/cras_audio_handler.h"
+#endif
+
 namespace extensions {
 
 namespace {
@@ -101,6 +105,12 @@ class ComponentLoaderTest : public testing::Test {
 #if defined(OS_CHROMEOS)
     local_state_.registry()->RegisterBooleanPref(
         prefs::kAccessibilitySpokenFeedbackEnabled, false);
+
+    // Tests on chromeos need to have the handler initialized because the
+    // Hotword component extension uses it to determine which extension to
+    // load.
+    if (!chromeos::CrasAudioHandler::IsInitialized())
+      chromeos::CrasAudioHandler::InitializeForTesting();
 #endif
   }